A former butcher "displayed" the severed head of a woman he killed deep inside a dark underground tunnel, a court in Britain has heard.

Tracey Woodford (47) was strangled by Christopher Nigel May a few hours after they met for the first time, prosecutors told Cardiff Crown Court.

Her dismembered body was found in May's Pontypridd flat on April 24th, while her head was later discovered 138 metres inside a storm drain near the town’s rugby club.

Prosecutor Roger Thomas QC described how officers made the grisly discovery.

"As soon as police walked into the tunnel, the first thing they immediately noticed was that it was completely pitch black. The pipe opened up into an underground chamber where water was cascading down".
"An officer turned to his right...and saw a human head laying down on its side on a ledge".

"One does have to consider what this involved: the defendant carrying a body part and a human head across Pontypridd into a dark tunnel, walking in for 138 metres".

"Most significantly, he removed the head from whatever it was being contained in".

"What was the purpose of displaying the head in that manner (on a ledge). He had ample time to do a number of things with it - at the very least bury it or put it in the dense foliage".

"Why would a man behave in this way with a woman's head? It is a very strange thing to have done - to put a head in this location".

The court heard May used to be a butcher and that a colleague had described him as "very good" at using boning knives, removing ligaments and spinal columns.

"It seems that his experience in the butcher's shop had been put to use on a human body," said prosecutor Mr Thomas.

May (50) admits causing Tracey Woodford's death but denies murder. The trial continues.